// Copyright 2019 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package resource

import (
	"github.com/gohugoio/hugo/common/maps"

	"github.com/spf13/cast"
)

func Param(r ResourceParamsProvider, fallback maps.Params, key interface{}) (interface{}, error) {
	keyStr, err := cast.ToStringE(key)
	if err != nil {
		return nil, err
	}

	if fallback == nil {
		return maps.GetNestedParam(keyStr, ".", r.Params())
	}

	return maps.GetNestedParam(keyStr, ".", r.Params(), fallback)
}
